Ahoy

google

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mid 18th century: from ah + hoy1.

wiktionary

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From "a-hoy", hoy being a Middle English greeting dating back to the fourteenth century. [1]

etymonline

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ahoy (interj.)

also a hoy, 1751, from a (probably merely a preliminary sound) + hoy, a nautical call used in hauling. The original form of the greeting seems to have been ho, the ship ahoy!